Production of hydroxy fatty acid (10-hydroxy-12(Z)-octadecenoic acid) by Lactobacillus plantarum from linoleic acid and its cardiac effects to guinea pig papillary muscles.

Lactobacillus plantarum produced 10-hydroxy-12(Z)-octadecenoic acid (10-OHODA) from linoleic acid. It was suspected that 10-OHODA might be closely related to leukotoxin (9,10-epoxy-12-octa-decenoic acid (LTx)) which was regarded as a toxic and/or defensive substance in living beings. The cardiac effect of 10-OHODA, which was biosynthesized by Lactobacillus plantarum, on an isolated guinea-pig papillary muscle was determined. Its effect on the contractile force of the tissue preparations was examined both in terms of its concentration and the time of exposure. A decrease in muscular tension was observed immediately after administration of 10-OHODA at concentrations of 30, 100, and 300 microM. We also compared the effect of 10-OHODA on muscle tension with that of LTx and its isomer 12,13-epoxy-9-octadecenoic acid (LTx'). Each inhibitory effect on the contractile force of the papillary muscle was statistically significant in the concentration of 300 microM 5 min after administration compared to the control in the absence of each fatty acid, suggesting that 10-OHODA is likely to exert some influence on the circulatory system together with LTx and LTx'.